or Tree Share (full tree read and write)—Certified to read and write Family Tree data to match, compare, and modify records. Also includes required certification for sources, discussions, change history, and interaction with community members.
or Tree Access (tree read only)—Certified to read Family Tree data to analyze, display, or print family history reports and charts.
or Sources (Tree Access or Tree Share required)—Certified to read Family Tree data allowing user to match and reference online “sources’ such as records, photos, documents, and media that provide evidence of events and relationships.
or Discussions (Tree Access or Tree Share required)—Certified to read, write, and comment on discussion threads for individual records in Family Tree.
or Change History (Tree Access or Tree Share required)—Certified to read and list changes made by contributors to the Family Tree, sources, and discussions.
or LDS Support (Tree Access or Tree Share required)—Certified that specific data and features for ‘LDS members only’ can only be accessed when the user is appropriately logged in to FamilySearch. Tree Access Certification is necessary for reading ordinance information. Tree Share Certification is necessary for requesting, changing, sharing, and printing Family Ordinance Requests (FORs).
Unless you have been using a FamilySearch Certified program, most of the distinctions between the various categories of programs may not mean a whole lot. Once you get into using the programs the distinctions become rather clear. If you refer to the page linked above, you will find the current list of Certified Products but bear in mind that the list changes as new programs are added or older programs are removed. You should also bear in mind that listing the programs on the product page does not constitute any kind of endorsement that the program will either function as you expect it to or even do what is claimed. I am not usually inclined to do program reviews for a variety of reasons but I can say that there are some programs which I think are invaluable and others which I hope not particularly interested in. Before purchasing a program you should always carefully review not only the claims made by the developers, but also product reviews if any of them are available from actual users of the program. This suggestion does not only apply to FamilySearch Certified Programs but to any software program that you purchase for your own use.